We plan to examine further the mode of storage of dopamine and norepinephrine in their respective central neurons and the mechanisms by which psychoactive drugs interact with these mechanisms. AT the present time our major interest is in the molecular sites of action of amphetamine and nonamphetamine stimulants on dopamine and noradrenergic neurons. Specifically we plan to examine the stereoselectivity of amphetamine isomers for their accumulation and binding to these neurons and to extend our previous findings from studies on synaptosomal preparations to membrane fragments so as to better dissociate transport phenomena from receptor binding.